Refrigerator



H. K. BEFGHOLM REFRIGERATOR Aug. 13, 1940.

Filed July 2, 1936 4 Sheets-Sheet 1 INVENTOR.

40; ATTORNEY.

Aug. 13, 1940. H. K. BE-RGHOLM REFRIGERATOR Patented Aug. 13, 1940 UNITED STATES PATENT OFFICE REFRIGERATOR Application July 2, 1936, Serial No. 88,578 In Germany May 7, 1935 Claims.

My invention relates to refrigerators, and more particularly to refrigerators of the pressure equalized absorption type. This application is a continuation-in-part of and replaces my application Serial No. 78,329, filed May 7, 1936.

In absorption refrigeration apparatus of the pressure equalized type the various elements or parts are permanently secured together, as by welding, for example, to provide a hermetically closed system. In order to facilitate the assembly of the refrigeration apparatus and the cabinet so that the evaporator can be readily arranged within the thermally insulated storage compartment of the cabinet, it has generally been the practice to provide a removable wall part or cover at an opening in one of the walls of the cabinet, and to extend parts of the refrigeration apparatus through such removable wall part with the evaporator arranged within.

the storage compartment.

The object of my invention is to provide arefrigerator cabinet having a removable wall part which is effectively utilized to house and insulate parts of a refrigeration apparatus, so that more space for other parts of the apparatus is provided in the apparatus compartment of the cabinet.

Another object of my invention is to provide a refrigerator cabinet having a removable wall part which is in open communication with the thermally insulated space of the walls of the cabinet, and to arrange parts of the refrigeration apparatus in the removable wall part to maintain the air in the thermally insulated wall space substantially dry and free from moisture.

Further objects and advantages of my invention will become apparent from the following description, and the various features of novelty which characterize my invention are pointed out with particularity in the claims which form a part of this specification,

In the drawings, Fig. 1 is a side elevation, partly in section, of a refrigerator cabinet in which refrigeration apparatus is mounted in accordance with my invention; Fig. 2 is a fragmentary sectional view taken at lines 22 of Figs. 1 and 3 illustrating the position of the evaporator in the storage compartment of the cabinet; Fig. 3 is a sectional view taken at line 3-3 of Fig. 2 illustrating the relative position of parts of the refrigeration apparatus shown in Fig. 1; Fig, 4 diagrammatically illustrates more fully parts of the refrigeration. apparatus shown in Figs. 1; 2 and 3; Fig. 5 is a fragmentary side view, partly in section, of a modification of the embodi-i ment illustrated in Figs. 1 to 3; Fig. 6 is a view taken at line 6-6 of Fig. 5; and Fig. 7 is a sectional view taken at line '|--'I of Fig. 5.

Referring to the drawings, I have shown my invention embodied in a refrigerator cabinet l0 comprising an inner metal shell II arranged to be supported within an outer metal shell l2 and insulated therefrom with any suitable insulating material, as indicated at l3. The inner shell ll defines a thermally insulated storage compartment 14 having an opening, and at the opening a door 15 is hinged to the front of the cabinet. The outer side walls of the cabinet form part of the outer shell I2 and extend beyond the-rear wall of the outer shell to provide a vertically extending refrigeration apparatus com-, partment it which is of substantially the same height as the cabinet.

Referring to Fig. 4, the refrigeration apparatus comprises a-generator ll containing a refrigerant in solution in an absorption liquid. Although I do not wish to be limited thereto, the refrigerant may be ammonia and the absorption liquid may be water. The generator ll is arranged-within a metal shell l8 which contains a suitable heat insulating material, as indicated at IS. The generator may be heated in any suitable manner, as by a gas burner (not shown), which is adapted to project a flame into the lower end of a flue which extends vertically upward through the generator. The heat applied to the generator andits' contents expels the ammonia out of solution, and the ammonia vapor thus expelled flows upwardly through an air-cooled rectifier 2| which condenses any water vapor which may be carried upward with the ammonia vapor. The water condensed in the rectifier drains back to the generator, and the ammonia vapor flows 11pward to an air-cooled oondenser'22 comprising a coil provided with a plurality of heat dissipating elements or cooling fins 23. The ammonia is liquefied in the condenser 22 by surrounding cooler air which flows over the surfaces of the coil and the fins, and the liquefied ammonia fiows through a conduit 24 into one end of an evaporator'coil 25, the conduit 24 being U-shaped as "shown most clearly in Fig. l, to provide a liquid seal. Y

An-inertgas, such as hydrogen, enters the end of the evaporator coil 25 opposite to that into which liquid ammonia is admitted. The hydrogen and liquid ammonia are in counter-flow, therefore, and the ammonia evaporates and diffuses into the hydrogen with consequent ab-' sorption or heat from the surroundings of the evaporator. The resulting gas mixture of ammonia and hydrogen, thatis, gas rich in ammonia, flows from the evaporator coil 25 through a plurality of parallel tubes 25 of a gas heat exchanger 2? and a vertically extending conduit 28 which communicates at its lower end with the lower end of an air-cooled absorber 29 comprising a looped coil provided with a plurality of heat dissipating elements or fins 30.

The ammonia is absorbed out of the rich gas mixture into weak absorption liquid which enters the upper part of absorber 29 through a vertically extending conduit 3i. The hydrogen, which is practically insoluble and weak in ammonia, passes upwardly from the absorber 29 through conduit 32 and the outer passage of the gas heat exchanger 27 into the evaporator coil 25, The gas heat exchanger 27 transfers heatfrom the weal; gas entering the evaporator to the rich gas leaving the evaporator to cool the gas entering the evaporator coil and thereby reduces the amount of cooling of the gas that takes place in the evaporator.

The absorption liquid flowing downward through the absorber. 29 in counter-flow to the gas mixture becomes enriched in ammonia and passes through the lower end of the conduit 28 to a vessel 33 which serves as an accumulation vessel for the absorption liquid. From the vessel 33 the strong absorption liquid flows through the inner conduit B l of a liquid heat exchanger 35 to a coil 36 disposed about the lower end of the flue 20. The rich absorption liquid is raised by thermosyphon action from the coil 35 through conduit 3? into the upper part of the generator ii. The absorption liquid is raised to a higher level in the generator I? than it is in the absorber 29, and absorption liquid weak in ammonia flows from the lower end of the generator through a conduit 38, outer conduit 39 of the liquid heat exchanger 35 and vertical conduit 30 into the upper end of the absorber 29. As shown most clearly in Fig. 4, the liquid heat exchanger 35 is arranged within a shell 40 which contains a suitable heat insulating material, as indicated at 4|.

In order to vary the total pressure in the refrigeration system just described with changes in air temperature, a vessel 42 for storing hydrogen is provided with one end thereof communicating through a conduit 43 to the lower end of the condenser 22 and the opposite end thereof communicating through a conduit 44 with the vertically extending conduit 28- of the gas circuit. The vessel 42 and conduits 43 and 44 provide a path of flow from the condenser 22 to the absorber 29, so that any hydrogen which passes through the condenser can flow to the gas circuit and not be trapped in the condenser. Further, should the air temperature increase so that ammonia is not liquefied in the condenser, the ammonia vapor will flow through conduit 43 to displace hydrogen in the vessel 42 and force hydrogen through conduit 44 into the gas circuit. This raises the total pressure in the system, so that an adequate condensing pressure is obtained for the increased air temperature. Refrigeration apparatus of the above type is generally described in Patent No. 1,609,334 to B. C. von Platen and C. G. Munters.

The manner in which the refrigeration apparatus just described is arranged in the vertically extending storage compartment H5 at the rear of the cabinet I0 is clearly shown in Figs. 1 and 3, with similar parts designated by the same reference numerals. The condenser and absorber coils are positioned with their fins 23 and 30 SD S d vertically within the compartment. The extended side walls and the rear wall 45 of the cabinet form a flue through which air flows upwardly over the surfaces of the absorber and condenser and fins secured thereto. If desired, the rear wall 45 of the cabinet may be provided with a plurality of apertures or openings to increase the amount of air circulating and passing over the condenser and absorber.

In order to arrange the evaporator 25 within the storage compartment 14, the rear wall of the compartment is provided with an opening having a removable wall part or cover 46. The cover 46 in the present embodiment is substantially the width of the storage compartment 14 and slightly wider than the evaporator coil 25, so that the latter can readily be placed in position within the compartment when the cover 46 is fitted into the opening.

The cover 46 comprises a rectangular frame 4? formed of suitable material, such as wood, having inner and outer metal liners or shields 48 and 49, respectively. The inner liner 48 is depressed about its peripheral edge so that, when the cover 46 is positioned at the opening, the greater por tion of the inner liner will be substantially flush with the inner shell I l and the depressed peripheral edge thereof will bear against a gasket 50 disposed about the opening in a recess formed between the frame structure 51 at the opening and the inwardly bent edges of the inner shell I I. The outer metal lining 49 is of greater area than the opening so that the peripheral edges thereof will bear against the outer shell l2. When the different parts of the refrigeration apparatus are mounted in the apparatus compartment It the cover 4.6 will fit tightly in the opening, so that the latter will be effectively sealed and form a dead air space between the frame structure 51 at the opening and the frame 47 of the cover.

In order to increase the amount of space available in the storage compartment l6 for housing different parts of the refrigeration apparatus, I arrange the gas heat exchanger 21 within the cover, 48. As shown in Figs. 1 and 3, the heat exchanger 21 is substantially horizontal and in its longitudinal direction is substantially parallel to the rear wall of the thermally insulated storage compartment. The heat exchanger 27 is embedded in a suitable heat insulating material 52 to support it rigidly within the cover and also prevent any condensation of moisture thereon.

The frames 41 and 5| about the cover 46 and at the opening, respectively, seal the thermally insulated wall space of the cabinet and cover, so that the likelihood of moisture in the surrounding air being absorbed by the insulating material is avoided. Since it is desirable to thermaly insulate the gas heat exchanger 21 to increase the efliciency of the refrigeration apparatus. the arrangement of the heat exchanger within the cover 46 effects a further saving in that additional insulation for the apparatus is not required as in the instances where the heat exchanger is located in the apparatus compartment of the refrigerator.

With the gas heat exchanger 21 in a horizontal position in the cover 46, the evaporator coil 25 is preferably arranged so that it also assumes a substantially horizontal position in the storage compartment l4. Since the portion of the evaporator coil 25 at the rear of the compartment is at a higher temperature it can be effectively used for space cooling, and, to increase the effectiveness of such space cooling, the rear portion of the evaporator coil 25 is provided with a plurality of fins 53. The forward section of the evaporator coil 25, which is at a lower temperature, is provided with a shelf 54 which maybe employed 5 to support trays for freezing water.

In Figs. 5 to 7 inclusive I have illustrated a modification of the embodiment just described, with parts similar to those shown in Figs. 1 to 3 designated by the same reference numerals. In

10 this modification the storage compartment I4 is thermally insulated by a plurality of sheets 55 of metal foil arranged in spaced relation in the space between the inner and outer metal shells II and I2, respectively, of the cabinet. The

15 sheets of metal foil are preferably very thin and may be formed of aluminum or other suitable material having bright reflecting surfaces which effectively reduce heat transfer due to radiation.

In order to maintain the air in the thermally 20 insulated wall space substantially dry and free from moisture", so that the foil insulation will not be damaged, openings 56 and 51 are formed in the frames 41 and 5|, respectively, of the cover 46 and the opening at the rear wall of the storage 25 ,compartment. The openings 56 and 51 provide ian open communication between the hollow cover 46 and thermally insulated wall space of the cabinet which permits circulation of air therebetween. Any moisture in the air is condensed on 30 the surface of the gas heat exchanger 21 and is collected in a vessel 58 arranged to be supported within the cover 46. The condensed moisture may be drained from the vessel 58 through a conduit 59, which extends through an opening 35 in the rear liner 49 and rests at its lower discharge end on the heated rectifier 2| whereby the moisture is evaporated. The conduit 59 is bent at 50 to provide a liquid seal to prevent surrounding air entering into the cover 46.

40 To the shelf 54, which is fixed to the evaporator coil 25, is secured an open ended shell 6|, as shown in Figs. 5 and 7, within which several trays 6| may be placed for freezing water. The cooling unit, comprising the horizontal evaporator 45 coil 25, fins 53, shelf 54, and shell 6!, is simple to manufacture and occupies a. minimum amount of space in the storage compartment l4.

.In view of the foregoing, it will be apparent that an improved refrigerator cabinet having a 5 removable wall part is provided in which such part is effectively utilized to house the gas heat exchanger 21, so that more space for other parts of the refrigeration apparatus, such as the absorber and condenser, is provided in the appara- 55 tus compartment l6 of the cabinet. Further,

by having the removable wall part in open communication with the thermally insulated wall space of the cabinet and arranging the gas heat exchanger in the removable part, the air in their- 60 mally insulated wall space is maintained substantially dry and free from moisture.

While I have shown and described several embodiments of my invention, such variations and modifications are contemplated as fall within the true spirit and scope of my invention, as pointed out in the following claims.

What is claimed is:

1. A refrigerator comprising a cabinet having thermally insulated walls, one of the walls hav- 70 ing an opening, a removable hollow wall part for closing the opening, said part being in open communication with the thermally insulated wall space of said cabinet when it is positioned to close the opening, refrigeration apparatus including a 75 generator, an absorber, an evaporator, a condenser, and means including conduits and a heat exchanger connecting said evaporator and said absorber, said heatexchanger being arranged entirely in said removable wall part.

2. A refrigerator comprising a cabinet having thermally insulated walls, one of the walls having an opening, a removable hollow wall part for closing the opening, said part being in open communication with the thermally insulated wall space of said cabinet when it is positioned to close 10 the opening, refrigeration apparatus including a 1 generator, an absorber, an evaporator, a condenser, and means including conduits and a heat exchanger connecting said evaporator and said absorber, said heat exchanger being arranged in said hollow removable wall part, and means cooperating with said heat exchanger for collecting moisture from air in the thermally insulating wall space that condenses on said heat exchanger.

3. A refrigerator comprising a cabinet having thermally insulatedwalls, one of the walls having an opening, a removable hollow wall part for .closing the opening, said part being in open communication with the thermally insulated wall space of said cabinet when it is positioned to close the opening, refrigeration apparatus including 'a generator, an absorber, an evaporator, a condenser, and means including conduits and a heat exchanger connecting said evaporator and said absorber, said heat exchanger being arranged in said hollow removable wall part, means cooperating with said heat exchanger for 001- lecting moisture from air in the thermally insulated wall space that condenses on said heat exchanger, and means for conducting moisture from said last-mentioned means to a heated part of said refrigeration apparatus to evaporate the moisture.

4. A refrigerator comprising a cabinet including inner and outer metal shells, said inner shell being arranged to be supported within said outer shell and spaced therefrom, means including thin metal sheets having bright reflecting surfaces arranged in spaced relation in the space between said inner and outer shells to provide thermally insulated walls for said cabinet, one of the walls having an opening, a removable hollow. wall part for closing the opening, said part being in open communication with the thermally insulated wall space of said cabinet when it is positioned to close the opening, refrigeration apparatus including an element arranged in said hollow wall part for condensing moisture from air in the thermally insulated wall space, and means cooperating with said element for collecting moisture that con-' denses thereon.

5. A refrigerator comprising a cabinet including inner and outer shells, said inner shell being arranged to be supported within said outer shell and spaced therefrom, means including thin metal sheets having bright reflecting surfaces arranged in spaced relation in the space between said inner and outer shells to provide thermally insulated walls for said cabinet, one of 6 the walls having an opening, a removable hollow wall part for closing the opening, said part being in open communication with the thermally inpart so that, when said part closes the opening, said heat exchanger is substantially in the plane of the wall in which said wall part fits, a vessel arranged within said hollow wall part for collecting moisture from air in the thermally insulated wall space that condenses on said heat exchanger, and means for conducting moisture from said vessel to a heated part of said refrigeration apparatus to evaporate the moisture.

6. A refrigerator comprising a cabinet having thermally insulated walls, one of the walls having an opening, a removable hollow wall part for closing the opening, said part being in open communication with the thermally insulated wall space of said cabinet when it is positioned to close the opening, refrigeration apparatus including an element arranged in said hollow wall part for condensing moisture from air in the thermally insulated wall space, and means cooperating with said element for collecting moisture that condenses thereon.

'7. A refrigerator including an absorption refrigeration system employing an inert auxiliary gas having a cooling element and a heat exchanger for gas flowing to and from said cooling element, a cabinet having thermal insulation walls forming a storage compartment, one of said walls having a removable section permitting insertion into said storage compartment of said cooling element, said gas heat exchanger being completely embedded in said removable wall section and extending in the plane of this wall, whereby the refrigeration system and cabinet are readily separable units, and said gas heat exchanger is completely insulated whether or not the cabinet and apparatus are assembled.

8. A refrigerator including an absorption refrigeration system employing auxiliary inert gasand having a cooling element and a heat exchanger for gas flowing to and from said cooling element, and a cabinet having thermal insulation walls forming a storage compartment, one of said walls having a removable section to permit insertion into said storage compartment of said cooling element, said gas heat exchanger being permanently sealed entirely within said removable wall section and extending in the plane 01' this wall so that it is permanently insulated thermally without the cabinet insulation being subjected to deterioration from condensation on said heat exchanger and without requirement of separable gaskets.

9. A refrigerator as set forth in claim I in which said cooling element is a pipe coiled in a generally horizontal plane, said removable wall section is horizontally elongate, and the gas heat exchanger in said wall section is elongated horizontally within the extent of said wall section.

10. In a refrigerator cabinet having thermal insulating wall structure comprising heat reflecting surfaces formed by spaced metal sheets or the like having high lustre surfaces, refrigeration apparatus having a cold part located in a chamber communicating with spaces between said insulation surfaces so that moisture removal by condensation on said cold part prevents tarnishing of said surfaces, and means for collecting moisture formed on said cold part.

HARRY K. BERGHOLM. 

